Patent GB-496045-A (GB)
Title: Process for the manufacture of motor fuel
IPC: C07C9/14
Filed: 1937-04-22
Abstract: <PICT:0496045/III/1> Liquid hydrocarbons, of saturated and principally of "iso" character, are obtained from hydrocarbon gases, consisting mainly of propane and butane, by co-operating steps in which the hydrocarbons are first catalytically dehydrogenated, the product is catalytically polymerized and separated into a non-condensible gas of high hydrogen content, an intermediate fraction comprising mainly propane and butane which are recycled and a polymeric liquid olefine fraction, and the said fraction is hydrogenated in the presence of the non-condensible gas to produce liquid paraffins.  In a suitable apparatus and method for carrying out the process the initial gases are forced by a pump 3 through a heater 6 to a catalytic chamber 11 wherein dehydrogenation is effected.  The issuing gas passes into a polymerizing chamber 19 whence the products pass to a condenser 26 maintained at a temperature suitable for separating the non-condensible gas from the remaining products and to a separator 29 from which this gas is taken off by lines 86, 91 for use in the hydrogenating chamber 62.  The liquid fractions from the separator pass through a heater 35 to a column 39 in which temperatures are maintained, approximating 52 DEG C. at the top and 163 DEG  C. at the bottom, whereby the propane-butane fraction is separated and is drawn off through line 40 cooler 42, receiver 45, pump 50, (a portion being drawn off for tower reflux), and returned through line 55 to the first stage.  The liquid polymers pass through line 57, pump 59, heater 601 to a catalytic hydrogenating chamber 62 together with reflux material from a fractionating unit 70.  The hydrogenated olefines (paraffins) and fixed gases are passed through a condenser 73 to a separator 76 from which gas is withdrawn at 77 and liquid paraffins at 79.  The catalysts employed in the hydrogenating step comprise carriers of refractory oxide and silicate type which are themselves catalytic on which are deposited compounds of titanium, zirconium, cerium, thorium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, alkaline earth and heavy metal salts of chromic, boric, carbonic, molybdic, pertitanic, permanganic and phosphoric acids.  Catalysts suitable for the polymerizing step may be of the solid phosphoric acid type such as are described in Specifications 437,188 and 464,671.  The catalyst mixture is heat treated to a degree such that the phosphoric acid on the carrier lies between pyro and meta phosphoric and approximates to the constitution of pyrophosphoric acid.  Liquid pyrophosphoric acid and heavy metal halides in solution, e.g. zinc chloride and stannic chloride, and also anhydrous metal halides, e.g. aluminium chloride, ferric chloride, zirconium chloride, may be used.  The dehydrogenating and polymerizing catalysts of solid granular type are regenerated by oxidizing gases. The hydrogenation of the olefines is conveniently effected by catalysts of moderate activity such as reduced nickel and the oxides and sulphides of chromium, molybdenum and tungsten. According to an example a mixture of propane and butane is dehydrogenated at 500 DEG C. and atmospheric pressure by passage over a catalyst obtained by reducing with hydrogen a composition consisting of chromium trioxide deposited on alumina, the product is passed at a temperature of 232 DEG  C. and 10 atmospheres pressure through a catalyst composed of 62 per cent pyrophosphoric acid and 38 per cent kieselguhr and the resulting olefines are hydrogenated at 427-454 DEG  C. and a pressure of 200 atmospheres using a molybdic oxide catalyst.ALSO:<PICT:0496045/IV/1> Liquid hydrocarbons, of saturated and principally of "iso" character, are obtained from hydrocarbon gases, consisting mainly of propane and butane, by co-operating steps in which the hydrocarbons are first catalytically dehydrogenated, the product is catalytically polymerized and separated into a non-condensible gas of high hydrogen content, an intermediate fraction comprising mainly propane and butane which are recycled and a polymeric liquid olefine fraction, and the said fraction is hydrogenated in the presence of the non-condensible gas to produce liquid paraffins.  In a suitable apparatus and method for carrying out the process, the initial gases are forced by a pump 3 through a heater 6 to a catalytic chamber 11 wherein dehydrogenation is effected.  The issuing gas passes into a polymerizing chamber 19 whence the products pass to a condenser 26 maintained at a temperature suitable for separating the non-condensible gas from the remaining products and to a separator 29 from which this gas is taken off by lines 86, 91 for use in the hydrogenating chamber 62.  The liquid fractions from the separator pass through a heater 35 to column 39 in which temperatures are maintained, approximating 52 DEG C. at the top and 163 DEG  C. at the bottom, whereby the propane-butane fraction is separated and is drawn off through line 40, cooler 42, receiver 45, pump 50, (a portion being drawn off for tower reflux), and returned through line 55 to the first stage.  The liquid polymers pass through line 57, pump 59, heater 601 to a catalytic hydrogenating chamber 62 together with reflux material from a fractionating unit 70.  The hydrogenated olefines (paraffins) and fixed gases are passed through a condenser 73 to a separator 76 from which gas is withdrawn at 77 and liquid paraffins at 79.  The catalysts employed in the dehydrogenating step comprise carriers of refractory oxide and silicate type which are themselves catalytic on which are deposited compounds of titanium, zirconium, cerium, thorium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, alkaline earth and heavy metal salts of chromic, boric, carbonic, molybdic, pertitanic, permanganic and phosphoric acids.  Catalysts suitable for the polymerizing step may be of the solid phosphoric acid type such as are described in Specifications 437,188 and 464,671.  The catalyst mixture is heat treated to a degree such that the phosphoric acid on the carrier lies between pyro and meta phosphoric and approximates to the constitution of pyrophosphoric acid.  Liquid pyrophosphoric acid and heavy metal halides in solution, e.g. zinc chloride and stannic chloride, and also anhydrous metal halides, e.g. aluminium chloride, ferric chloride, zirconium chloride, may be used.  The dehydrogenating and polymerizing catalysts of solid granular type are regenerated by oxidizing gases. The hydrogenation of the olefines is conveniently effected by catalysts of moderate activity such as reduced nickel and the oxides and sulphides of chromium, molybdenum and tungsten. According to an example, a mixture of propane and butane is dehydrogenated at 500 DEG C. and atmospheric pressure by passage over a catalyst obtained by reducing with hydrogen a composition consisting of chromium trioxide deposited on alumina, the product is passed at a temperature of 232 DEG  C. and 10 atmospheres pressure through a catalyst composed of 62 per cent pyrophosphoric acid and 38 per cent kieselguhr and the resulting olefines are hydrogenated at 427-454 DEG  C. and a pressure of 200 atmospheres using a molybdic oxide catalyst.